


Twins Are Dangerous: Byleth (Female)

by theflyingpan



Series: Twins_Are_Dangerous_AU [7]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Major Spoilers, Minor Spoilers, Twin AU, Twin Byleths, Twins_Are_Dangerous AU, i suck at tags sorry, it's finally time my dudes, typical cannon violence
Language: English
Status: In-Progress
Published: 2019-11-07
Updated: 2019-11-07
Packaged: 2021-01-24 18:51:23
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 10,199
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21343036
Author URL: https://archiveofourown.org/users/theflyingpan/pseuds/theflyingpan
Summary: Sothis felt sort of bad for the child; After all, it’s not really her fault that no-one in the monastery was expecting their mother to birth two children instead of one, it’s not Byleth’s fault that she was born after her brother, and it was certainly not her fault that it was her birth that killed her mother.Part of my Twins_Are_Dangerous AU. You don't need to read Jeralt's story, but it provides a bit more background. You probably should read Male Byleth's story, as the two are closely connected- like the twins.
Series: Twins_Are_Dangerous_AU [7]
Series URL: https://archiveofourown.org/series/1465258
Comments: 2
Kudos: 14





	Twins Are Dangerous: Byleth (Female)

**Author's Note:**

> This is the first part of the Twins Are Dangerous AU with the twins in the spotlight this time! This part follows the twins from birth up to the day they meet the three house leaders through the eyes of Female Byleth, and will explore my personal head cannons for the twins and their birth.  
Warning! I have not played through the entire game and as a result I don't know all the cannon details, so most of this is my head cannons and theories thrust into an AU.

When Byleth was born, a full three minutes after her brother crying and burning from a fever, Sothis had no idea what to do with her—Lady Rhea was far too busy placing a crest stone in Byleth’s older brother in an attempt to save the male’s life and Byleth’s feverish cries and soft whimpers nearly fell on deaf ears as Rhea ignored the girl in favor of saving the male. Sothis felt sort of bad for the child; After all, it’s not really her fault that no-one in the monastery was expecting their mother to birth two children instead of one, it’s not Byleth’s fault that she was born after her brother, and it was _certainly_ not her fault that it was her birth that killed her mother. Byleth also had a horrible fever burning through her infant systems and killing her slowly, which she probably contracted in the womb that only got worse once she was pushed out. Sothis frowned as she was pulled closer and closer to the male child due to the crest stone soon to be implanted in his body, stealing glances at the infant on the other side of the table who was getting quieter and quieter. Sothis used her still awakening powers to start the creation of a magic tie on the male as she floated past him, activating the crest stone Rhea was placing in him and allowing him to use it as a heart, before she stopped above the girl. Byleth was barely breathing, her body burning with a high fever, and Sothis gave her a sympathetic smile.

“Oh little one, you’ll be alright” Sothis promised, placing her hand on Byleth’s bare chest. As the crest stone glowed from the boy’s chest, a similar glow appeared on the girl’s chest in the same area, and Sothis smiled as she connected the two. She pushed herself into the female’s body, gently taking Byleth’s soul and placing it on a stone throne.

“Here we go, just rest here for a little while” Sothis smiled as Byleth stopped crying, her soul taking the form of an infant that curled up on the throne. Sothis closed her eyes as well, and when she opened it again, she viewed the outside world though light blue eyes that blinked against the harsh light. A small whimper left her mouth as she shivered from the cool air, which caught Rhea’s attention before she could escape the room with the boy twin in her arms. Soon, Sothis was wrapped up in a soft blanket, held against Rhea’s chest with Byleth’s brother and carried out the room to where Jeralt awaited his wife and child. The body she occupied lulled Sothis to sleep, only waking again when placed in a small cot by a stone faced Jeralt, his tears long gone. He smiled a bit as Sothis wiggled, testing her new body’s movements, but when he gently moved her to lay closer to Byleth’s brother, she stopped moving. Sothis stared at his sleeping face, satisfied with her work, and the gentle rise and fall of his chest helped her fall asleep again.

((Sothis was barely awake when Jeralt whispered the names of the boy and the body she occupied, but heard it all the same. She held back a snicker when she found that also shared a name with the boy next to her, not just a heart.))

* * *

When Byleth was wrapped tightly in a bundle next to her brother, as their father burned a way out of Garreg Mach, Sothis felt something pulling her spirit back to the burning building looming behind them. She wiggled in Jeralt’s arms, trying to see what was still back there, tying her to the place, but Jeralt simply tightened his grip and urged his horse to move faster. Sothis let out a small whimper as the pull turned to a sharp tug, and Jeralt suddenly stopped his horse, acutely aware of the bundle he held preciously against his body. He opened the blanket he wrapped the twins in, and Sothis stared at him blankly as he ensured his kids were safe. She saw his face, twisted with worry and regret, as he let out a small breath in relief. She frowned as he re-wrapped the infants and was suddenly pulled close to the man’s chest as he continued to escape. Byleth, still sleeping soundly, wiggled as the horse jolted into a run, and Sothis ignored the tugging she felt by gently resting a tiny hand over his chest. Her warmth helped the boy settle down, and Sothis herself decided to nap as the tugs grew weaker and weaker.

((Jeralt could barley make out the details of his kids, but using the light from the fires behind him, he was able to check and ensure that he had both his daughter and his son safely tucked into the bundle of blankets. His actions made his daughter wake up and stare at him and— he swore it was the strange lighting of the environment— it almost looked like his daughter’s eyes were a bright green instead of a dark blue.))

* * *

When Byleth was an infant, Sothis made her cry out often. She cried when the body demanded food, whined when she needed to be cleaned, and whimpered softly when she was tired yet her body refused to sleep. Sothis wanted to ensure that the body she inhabited was healthy and grew up well, but she also had to ensure that Byleth’s brother lived and grew up to be healthy. So, since she couldn’t outright tell Jeralt “make sure that he doesn’t die because I will die too also im just occupying your daughters body for a bit haha”, she just made noise for the boy who was near silent. When she noticed he was hungry, she cried loudly and wiggled her tiny body. When he needed to be changed Sothis ensured her whines rung in Jeralt’s ears until he finished cleaning the boy’s body. The only time she didn’t cry for the brother’s needs was when he needed to sleep. Sothis tried to help the boy sleep on her own, letting Jeralt get some well deserved rest, but one day he had enough with Sothis’s “help”.

“Here” Jeralt sighed, picking his daughter up and setting her on a spare jacket on the floor. He used the fur lining to cushion the girl’s head as she rested against the wall, and set a small hand mirror at her feet. He had gotten some advice from parents around the towns he stayed in, and found that infants enjoyed seeing their own reflection— something about observing the world and mimicking actions or something, he wasn’t really paying attention. He left Sothis on the ground and walked across the small room to pick up his son and cradle him to sleep.

‘Lucky’ Sothis hummed in thought, wanting to sleep as well, but instead shifted her focus on the object in front of her. It was a simple hand mirror, and Sothis admired the decorative carving on the handle by running a small hand down it. She leaned over and gazed at her reflection, and her metaphorical heart stopped. There was a small girl staring back at her, with blue eyes matching a few locks of blue hair. The girl was staring eyes wide at Sothis, and she got to see clearly the slight confusion swirled in the blue pupils. Sothis slowly opened and closed her small hands, frowning as the girl in the mirror did the same thing. She gently tapped the mirror, and stared at the uncomfortable blue color so unlike the green she was first expecting. Sothis watched as the girl in the mirror pat the blue tufts of hair and slowly realized that _she_ was touching _her_ blue hair. Maybe it was because she was in an infant’s body, or because she hasn’t had a body in so long, but something in Sothis snapped.

‘That’s not me’ She realized, staring at Byleth’s body. ‘That’s not my body…this isn’t me…I don’t have blue hair! I have beautiful dark green hair and bright green eyes! I don’t want this! I want to go back now! I don’t….I hate this…’ Sothis felt herself spiraling into despair, as the weight of her decision finally settled in and she realized exactly what she let happen. She barely noticed the tears streaming down her face, not realizing that she had covered her eyes and started to kick the mirror away. She was still spiraling when Jeralt rushed over and gently cradled her body, cooing at her and attempting to calm the infant down.

“Shh shh, Byleth, it’s alright dear” He called gently, and that only further broke Sothis.

’That’s not my name! I’m Sothis! That’s not me!’ Her lips quivered and she started to wail, trying and failing to vocalize her thoughts. Jeralt cursed and grabbed his coat from the ground, wrapping up his daughter as she started to push away from him. He avoided further use of her birth name as he slowly calmed her down and lulled her into a deep sleep, the rumble of his deep voice grounding Sothis’ thoughts and allowing her to focus. She whimpered softly and closed her eyes tight, feeling another force deep inside her move the body. She felt Byleth, the real infant girl, slightly awaken enough to cling to her father’s body as the two fell asleep—and for once, Sothis didn’t make a sound.

((Jeralt sighed as his daughter finally calmed down, glaring at the hand mirror for making his sweetheart cry so violently. He set the girl down in the cot next to her brother, watching as the boy unconsciously moved to hold his sister’s hand. Jeralt smiled weakly before sighing. He wished he had the strength to change Byleth’s name, since she always reacted weirdly to it— but his heart still ached from loss and he couldn’t bear to even hear his wife’s name, let alone speak it.))

* * *

When Byleth was old enough to walk around and follow her brother carefully around mercenary camps and small towns, Sothis found it was getting harder and harder to simply accept her new appearance. Granted, she didn’t have any more meltdowns about her blue hair and eyes, but she still hated the way her reflection clashed with her inner perception of her body. So, she opted to avoid any reflective surfaces; any curtains were pulled to cover the window of their inn rooms when she could reach them, puddles of water that Byleth’s brother kicked his boots in were kept at a safe five foot distance, and when the band of mercenaries stopped by rivers or streams to tend to their horses Sothis found a way to steer clear from the water’s reflection, knowing that the blue of the water will meld into her blue hair. When Jeralt called their names from across the ways, either wanting to give them a small task or instruct them to stay safe, Sothis simply closed her eyes and pretended he only meant to call the male, sometimes gently taking his hand to lead him to their father. She let this continue for a total of five years, until the twins woke up on their birthday feeling refreshed and healed. Literally, _both_ of the twins. Moments before her brother woke in the physical world, Byleth’s spirit awoke in Sothis’ mind, rubbing her eyes and sitting up in the stone throne Sothis placed her on five whole years ago.

“Oh thank goddess, you woke up!” Sothis sighed with a relieved smile. The girl tilted her head a bit, and Sothis walked over to stand in front of the throne. She looked Byleth up and down, her smile fading when she realized the girl was still an infant, not having aged at all. “Oh my, this is certainly an issue…” She frowned at the child, who simply stared blankly back. “Well, I am _not_ going to wake up—you can have your body back miss.” A slow blink, and Byleth’s head tilted slightly. “Hmm, curious, you seem to understand me enough to be confused…” Sothis shook her head and gently raised Byleth up, sitting down on her throne with the girl in her lap. “Okay, how about this. You can go back and use your body, while I stay awake and help you get used to things.” She yawned and the babe wiggled in her arms. “Let’s hope you are a fast learner, I can feel myself falling asleep already.”

— —

Jeralt stared blankly at his kids. His son was already dressed, standing by the shared bed in the inn with his sister’s coat in his hands. His sister was still on the bed, sitting crossed legged and simply staring at her brother, and still in her nightgown.

“By- um, sweetie?” He called, catching himself before he called her name. His daughter didn’t move, still staring at the coat in her brother’s hands as if she never saw the article before. “Byleth?” He tried again, and his son turned to stare at his dad and offer a small shrug. Curiously enough, his daughter did react this time, and she turned to stare at him without tears in her eyes. _That_ was new. Jeralt walked over, taking the coat from his son’s hands gently and kneeling in front of the bed.

“What’s wrong?” He pressed, placing the coat on her lap. “It’s time to get going, we have a long ride ahead of us.” His daughter stared at the coat, curling her hands in it as she looked back at him, tilting her head slightly at his words. He sighed and simply chalked up her strange actions as sleepiness, and helped his daughter dress herself. He packed up the remaining belongings in the room before walking to the door, his son just steps behind him. “Alright, lets get moving” Jeralt called, holding the door for his son before blinking and looking back into the room at his daughter.

‘Hold on! Jeez this man is so impatient!’ Sothis sighed, and she focused back to Byleth. ‘Come now, it’s not too hard, just start slowly’ Byleth, guided by Sothis’ words of encouragement, slowly took her first steps, wobbling a bit as her infant mind got used to moving the five year old body. Jeralt raised an eyebrow as his daughter carefully walked to the door, raising it higher as she fell twice on the way over. When Byleth made it to the door, she smiled slightly and used the doorframe to shimmy her way out of the room fully, finally allowing Jeralt to close the door. He and his son shared a confused look before his son took Byleth’s hand and started to walk to the stairs. Jeralt walked behind the two slowly, since his daughter was still walking weirdly and was now using both her brother’s hand and the wall of the hall as support. It was almost as if she was learning to walk again, and he stopped as he watched her sit on her bottom and scoot down the stairs like a child.

‘It is certainly easier this way, but…’ Sothis hummed at Byleth’s method of descending the stairs before Jeralt interrupted her next comment.

“Byleth, honey, is something wrong with your legs?” Jeralt walked past his son to kneel beside his daughter, who was sitting halfway down the stairs and still trying to scoot down.

‘Ah, he’s onto us! I doubt you can talk and explain anything right now, just stand up!’ Byleth stood suddenly at Sothis’ urges, gripping the railing of the stairs and taking in her father’s confused face. ‘Don’t worry, he’ll catch you if you fall’. Apparently, those were the wrong words to comfort the child, as Byleth shrunk in on herself as she stared at the rest of the stairs she had to walk down.

“Well, let’s get you to the mage then” Jeralt sighed, interrupting Byleth’s thoughts and picking his daughter up. He looked back to his son, who was wearing a small frown, and decided picked him up too. They walked down the stairs and to the counter, where Jeralt paid for their stay, before walking out the door and into the town. Byleth closed her eyes a bit at the sunlight peaking through the clouds before Jeralt placed her back down on her feet. Sothis smiled as Byleth managed to keep her balance and not fall over right away, _small_ victories. “Think you can walk from here to the stables?” Jeralt asked gently, and Byleth just gave him a blank stare.

‘That’s not too far away, I think we might be able to manage with your brother’s help’ Sothis explained, and Byleth nodded and grabbed onto her twin’s hand. He looked a bit confused, but resolved to helping his sister walk to the stables with their father. Jeralt instructed them to stay by the entrance while he located their healer mage, but Sothis saw the way Byleth’s eyes wandered around to gaze at the animals in the building.

’That’s your dad’s horse, the white one right here’ She hummed, and Byleth turned to inspect the white horse her brother snuck over to pet gently. She looked around for any sign of her dad before slowly toeing her way over to join her twin. ‘She’s actually very gentle, just copy your brother and she’ll let you pet her’ A confused blink. ‘Hold your hand out, and let her sniff you, then she’ll let you touch her.’ That must’ve made sense, as Byleth did exactly that. Her brother watched with a thoughtful look as the horse gently licked his sister’s hand and leaned down to let her burry her hand in the hair.

Byleth clutched the hair before quickly letting go, moving to instead gently pat the animal mechanically. Her brother watched silently with calculating eyes, and Jeralt finally walked over with the mage that recently joined their group.

“Byleth, come here and lets take a look at those legs” He called out, causing Byleth to turn and move her hand off his horse.

‘Oof, this will be a challenge’ Sothis sighed, ‘I doubt you’ll be getting any help again, just take your time, alright?’ Byleth hummed a bit in agreement, and she slowly walked over to the open space where her father and the healer waited. The mage raised a confused eyebrow and knelt down to Byleth’s height as she finally made her way over, Sothis beaming as Byleth managed to keep her balance the entire time.

“This is…certainly something…” The mage thought aloud, gently reaching out and taking Byleth’s foot.

‘Woah! Quick grab onto something!’ Sothis managed to warn in time, and Byleth buried her hands in the woman’s cloak as her right foot and leg was inspected. Her brother had joined her by now, and Jeralt put a hand on his son’s head as the two watched the Mage poke and prod at Byleth.

“I can’t find anything wrong sir” The mage finally sighed, letting go of Byleth and standing to talk to her father. Sothis sighed in relief as Byleth backed up a bit, but Jeralt sighed with a bit of stress in his tone.

“Well I don’t know what happened. All of a sudden she was walking weirdly, like she was learning how to walk all over again.” He shook his head, and his son walked around his legs to stand next to his twin. Sothis hummed a bit uncomfortably as he stared Byleth up and down, not saying a word, before he simply fixed her coat and held her hand. Sothis smiled a bit at this, and the twins stood together as their father talked with the healer.

‘This will pass’ Sothis decided with a nod, as the man finally shook his head and waved the woman away. ‘He’s just confused, as I expected, with your mind now back in it’s proper place. No need to worry, you will soon get used to living.’ She smiled, proud of her work, and Jeralt picked up his kids and settled them onto his horse. Byleth wiggled a bit and attempted to move around her brother’s body to pat the horse’s head again, but Jeralt placed a hand at her middle and pulled the two close to his body. He nodded at his group and they started off on their ride, with the twins tucked against his body as they moved.

‘Time for a quick nap’ Sothis yawned, and Byleth was soon alone in her thoughts. She looked around at the forest the group moved in, looking at the light shining through the leaves and listening to the gentle chirps of birds as they woke up. She didn’t notice the way her brother stared at her, far too busy taking in the sights of a world she missed out on by sleeping for five years to notice his thoughtful stare.

((Later that day, when the group had found an open area to set up camp for the night, Jeralt surprised the kids with a matching pair of medallions. He tied one around his son’s waist at his request, and gently pinned the other on his daughter’s shirt, just under her neck. The two sat close together, examining the matching pieces of metal, and Jeralt let his worries about Byleth’s health melt away.))

* * *

When Byleth was finished with her work, she pushed the pad of paper over to her father seated across the table with a satisfied sound. Her brother was reading a book next to her, mouth turned down slightly as he practiced reading, and her father picked up the paper as his own mouth twitched to frown as well.

‘Well, at least it’s amusing how similar the two are,’ Sothis tried to comfort as Jeralt sighed and shook his head for the third time since he sat the twins down to practice their reading and writing.

“Byleth dear I thought we had this down, how do you keep making these mistakes?” He asked gently, as he circled parts of the sentence she was tasked with writing. His words caught her brother’s attention, who glanced up from his book ever so slightly. Jeralt stood and walked around to kneel next to his daughter, and gently handed the papers back. “Look Byleth, you got the ‘B’ and ‘D’ mixed up again” He sighed, and both Byleth and Sothis looked at the words.

‘Hey you got the ‘B’ in Byleth correct, there’s that at least!’ Sothis commented, but the truth was that Byleth still misspelled the words ‘sword’ and ‘battle’. Byleth made a small noise before taking the quill and carefully rewriting the sentence. Jeralt watched her in silence, only looking away to gaze at his son. He was also watching Byleth write her words again, but quickly stuck his nose back in his assigned book when he felt his father’s gaze. Jeralt focused back on the words his daughter wrote and gently placed a hand over hers, causing her to pause.

“Byleth…? Do you even know what this _says_?” He asks gently, and watched as she stared back at him blankly. He sighed and scratched the back of his head. “I guess I shouldn’t except you to speak to me or anything…” He muttered, but shook his head and ignored Byleth’s look. “Just…let’s read with your brother.” He sighed, gently taking the book from his son’s hands and walking to the bed in their borrowed room. Byleth walked over with her brother, who helped her climb onto the bed, and the twins sat on either side of their father. Sothis supposed she had something to do with it, because soon after the man started to read the words to the children in hopes of teaching them to understand, Byleth fell asleep against his shoulder. Sothis sighed and was about to move to wake the girl up, but realized that Byleth’s brother had also fallen asleep.

‘It’s been a long day I suppose’ She hummed, settling down and deciding to listen to Jeralt’s story in their place.

((The next day, when the men were cleaning up the camp and getting the horses ready to move, Byleth walked to her father and tugged at his pants leg, calling out his name. Both Jeralt and Sothis teared up a bit as the girl spoke her first word, and the twins were quickly pulled into a hug. Byleth and her brother shared a look before gently hugging back, the pad of paper with perfectly written words forgotten in Byleth’s hands.))

* * *

When Byleth and her brother started to lean self defense, Sothis was starting to feel herself getting more and more tired. Well, its not like she _wasn’t_ napping alongside the female or anything, but Sothis could feel her magic weakening and the urge to sleep for decades to regain her strength was starting to be more pressing. While Jeralt taught the kids self defense in order to fight for themselves, Sothis was fighting the random spells of sleepiness and the effects it had on her host.

“Byleth?? Are you paying attention??” Jeralt called out, jolting Byleth and Sothis out of their half asleep state. The man stood a few feet away, currently holding his son in a hug from behind as the child fought to slip out of his father’s grip. “Can you repeat what I said?” Jeralt pressed, not batting an eye as his son started to bite his arm.

“…You said…that fighting back…won’t, won’t always…work…” Byleth repeated quietly, loud enough for her father to hear at least. Sothis breathed a sigh in relief as Jeralt nodded at the words, and the boy in his arms finally got the message and stopped fighting. Byleth watched as her brother went limp in their father’s arms, which allowed him to finally slip out of the grasp and get on his own two feet. Jeralt smiled and ruffled the boy’s hair before motioning his daughter over.

“Good work, glad to know _someone’s_ paying attention.” He teased, and his son just narrowed his eyes slightly at him. Byleth’s brother still hasn’t spoken a word, not even to Byleth herself, but Sothis could not wait for the boy’s patience to snap and for him to spill out all the vile words she knew he held back—it would be _very_ entertaining. Jeralt focused his attention on his daughter, looking between the twins before finally nodding.

“Okay, I think you two are ready,” The twins perked up at his words and he smiled at them. “Shall we start training with weapons?” Byleth nodded with her brother, and the two followed Jeralt closely as he walked to the tent that housed the group’s spare weapons. “I got these the other day, they should work nicely for practice.” He explained and held out two wooden swords for the twins. Byleth took the weapon gently and turned it in her hands, and her brother grabbed the sword with eyes wide in excitement.

‘Hmm, this feels….’ Sothis frowned as she struggled to name the feeling she felt as the sword in Byleth’s hands.

“…Right…” Byleth finished for her, and Jeralt turned to look around for the source of the sound. When Byleth didn’t speak again, he shrugged it off and picked up a training sword.

“Okay, lets get you two started,” He smiled at them, and soon the three were back at their makeshift training grounds, learning the ways to hold a sword as well as how to use it. Jeralt tasked the twins with a few simple formations to practice as he took off, walking around the camp to check in on his men and get the details of their next mission worked out. Byleth worked along side her twin as they moved in eerie sync and in even eerier silence. Sothis felt herself falling asleep, yawning and allowing herself to just close her eyes a bit…but she suddenly was jolted awake.

‘Huh? What? What happened what’s going on?’ She demanded and looked around. Byleth had dropped her sword and was shaking her head, frowning a bit. ‘What? Did something happen??’ Sothis pressed, but Byleth ignored her in favor of taking the sword from her twin’s hands.

“…Dizzy…” She explained to both Sothis and her brother, who took the explanation without words and continued to practice on his own. Sothis frowned a bit at this.

‘That won’t do, you’re using weapons now, lets get you focused okay?’ Byleth nodded and continued to run through the drills, only feeling dizzy twice.

“Alright, I’m done for now, lets get some real practice in you two!” Jeralt called out, walking back to the twins. Byleth turned to face her dad, but was hit with another dizzy spell as she moved to join her brother. She swayed and nearly fell over, but just as her brother and father moved to catch her, Sothis snapped out of her own daze and allowed Byleth to regain control and snap her foot out, keeping her balance.

‘…I believe that is my doing…’ Sothis muttered, and Byleth sighed a bit before looking up at her family. Jeralt had all but lunged for his daughter, and Byleth was lying on the ground ready to catch his sister. She blinked at the two before taking half a step backwards, trying to explain what was going on.

“…I…I’m better, now” Byleth murmured, and the men simply sighed in relief and stood back up.

((Sothis couldn’t fight off her sleep spells forever, which caused Byleth to have more dizzy spells as the days turned to weeks. Luckily, the girl was quick on her feet and never managed to fall over, but she did give her brother and father quite a few more heart attacks with close calls. Byleth developed a method to ensure she never fell over, always managing to snap out of her daze to correct her balance.))

* * *

When Byleth and her brother were finally allowed to join Jeralt in combat, Sothis had finally lost the battle against sleep. It wasn’t a huge loss, she would just leave Byleth’s body and rest in the magic space that connected the twins instead—which would allow her to regain some of her magic that she lost when she saved the twins’ lives. Sothis yawned as the twins got suited up in light armor and were given instructions by their father as they got ready to help the mercenary group reclaim some items stolen by a group of thieves. Jeralt had determined based on the items stolen and the way they were taken that the thieves were small timers, beginners at the craft who picked their targets badly, and thought it was safe enough to let the twins help out. He tried to shake the unease he felt as they got into position in front of the cave turned hideout, and Sothis tried to shake off her drowsiness. She watched as Jeralt lead the attack, and Byleth and her brother stayed behind to provide cover and ensure no thief slipped away. That soon changed when the thieves, who had realized they were being ambushed, scrambled to fight back with both weapons and magic—something that threw a huge wrench in Jeralt’s otherwise flawless plan. He cursed as he and his men were pinned behind rocks, unable to enter the cave with the waves of arrows and magic the group of thieves kept hurling their way, and was just about to call for a new battle plan when he heard the clashing of swords. Jeralt turned to see some of his men engaging with some of the thieves who emerged from the cave’s mouth and cursed as the group pushed out of the cave using the cover of the archers and mages to their advantage. Sothis gasped as she was hit with a sudden and sharp wave of drowsiness, strong enough to give even the male twin some discomfort. Unfortunately, that allowed a stray arrow to pierce his shoulder and knock him backwards. Byleth fought off her own dizziness as a lone thief carrying a stolen sword jumped over their cover and stalked to her brother on the ground. Panic flooded Jeralt’s body, but before he could even think of moving, Sothis passed out and slipped away—her spirit carried off to rest in the connection between the kids. Her dizziness gone, Byleth reached behind her and all but threw two arrows at the man over her brother, forgetting her bow in favor of speed. The man fell to his side and cried in agony as the arrows hit him, giving Byleth just enough time to breathe and rip the arrow out of his shoulder. Byleth rushed over and the two used the improvised weapons to stab the man’s face, an arrowhead for each eye. Jeralt fought off the urge to puke, only resolving to talk to the two later and instead focused on tearing through the rest of the men. Byleth blinked away the blood that shot out of the man as he died, helping her brother stand. She felt empty, and when she tried to reach Sothis, she got no response. As another arrow nearly took her ear, Byleth shifted her focus on providing her father cover with her bow as her brother started hurling his hand axes.

((Later, after her brother spoke for the first time in his life and after her father scrubbed the blood out of her hair, Byleth laid in bed and tried to find any traces of the girl she grew up with. After being met with silence for nearly an hour, she frowned and turned over in bed. Her brother’s breathing comforted her, and she fell asleep with the resolve to ensure he didn’t leave her as well.))

* * *

When Byleth watched her brother wander away from the group when they explored the new town, she felt a small tug in her chest. She attributed it to fear (or what she understood as fear from her father’s explanations), and walked off with him to stand next to him in front of a weapons shop. He gazed at her before shifting his focus back on the window display, causing Byleth to look as well. There were quite a few weapons on display, with ornate handles and blades designed for display and not combat, but her eyes were drawn to a set of daggers with bright blue handles. She didn’t notice the way her hands gently touched the glass with her brother’s, or the way the two leaned closer to the glass to inspect the blades. It wasn’t until a heavy set of footsteps started to approach them did Byleth stop staring into the window to turn to stare at her father, not realizing that her brother did the same thing. Jeralt chucked as he kneeled down so the twins were just above eye level, raising an eyebrow.

“You two want something?” He asked, and Byleth glanced at her brother for an answer. He gave her a blank stare of disinterest, but Byleth could see in his eyes some sparkle of interest. She turned over the options in her head before slightly shaking her head at the same time as her brother at Jeralt’s question.

“N-no thank you..we’re okay…” Byleth mumbled, her voice getting smaller as she finished her sentence. She heard the gentle sigh of relief from her brother, and despite the desire they had for wanting to own such a blade, the twins knew that there was no practical use for the decorative weapon. Byleth was vaguely aware that neither her or her brother felt this sort of desire to own anything before, but ignored it in favor of giving her father a blank stare, trying not to betray her words. Jeralt gave them a hard stare in return before standing and walking inside the store.

“Excuse me?? How much for the blue dagger set?” He called out, smiling as the twins run in after him. Byleth certainly wasn’t expecting him to do that, and by the way her brother tugged on Jeralt’s cape in protest she could tell he didn’t expect it either. But soon enough, the twins were standing outside the store with identical blue handled daggers, holding the weapons in their hands as Jeralt dropped the rest of his change into a coin sack. He smiled and ruffled their heads in sync, smiling at his kids. “It’s okay to _want_ things, you know” He explained, and Byleth turned the thought over in her head for the rest of the day. She never felt the urge to want something before—well, at least not _physical_ things. She _wanted_ Sothis back, to talk with her and hear the girl’s voice. She _wanted_ to be able to speak without pause, or without repeating herself. More than anything else, she wanted to protect her brother. Her desire to keep him safe is what caused her to fall asleep clutching her new dagger close to her body, falling asleep and having a dreamless slumber.

((Byleth swore she heard a small, familiar voice, explain to her that her brother could not die, that he needs to be protected at all times. But when she woke the next day, her head was quiet, and she ignored the sharp pang in her chest that lasted the rest of the day.))

* * *

When Byleth first heard the words, she was passing some of the men in their group with an armful of bloody weapons. Her brother was already at the river near the camp, attempting to wash the blood off his cape, and she simply ignored the words and focused on the task at hand. The second time she heard the words, they were spilled from drunken lips as the men celebrated another job well done. Their boss nowhere in sight, the men of the band took the opportunity to poke and prod at the two stoic twins, alcohol giving them the courage to even dare speak to the creepy twins.

“The waaayyy those two -hic- dismembered that mage, ‘member thaaat?” An archer laughed, jabbing a finger into Byleth’s chest as he nudged his equally drunk companion. Byleth simply blinked at the two as they shared a drunk laugh. “They were like….what was that word Mike used…?” His companion laughed.

“Aaaashen deeemons!” He slurred, and the two laughed and threw back another drink. Byleth turned to face her brother, who gave her an equally confused look, and the two decided to slip away from the men. They passed their father on the way back to their tent, ignoring the laughter their departure caused and the calls of “Demons!” the men yelled after them. Jeralt smiled a tipsy smile at his kids before walking to join his men, and Byleth stared at his retreating back before her brother tugged her into their tent. She slept soundly that night, never expecting the nickname bestowed on them to stick and grow. Soon, just as Jeralt caused men to whisper about the many exploits of the legendary “Blade Breaker”, the twins started to cause the same men to quietly mutter to each other about the ruthless nature of the twin “Ashen Demons”. Byleth couldn’t describe the way the name made her feel, but she and her brother simply let the words wash over them. She continued to kill and fight alongside her brother and father, finding herself not caring when women started to move their kids away from her as she stood with her father to purchase food at the local markets, or when children would freeze up when they got too close to the “scary girl” during play. She simply learned to stay close to her brother, who kept her company when everyone else started to distance themselves.

((Jeralt sat them down one day to discuss their infamous reputation, not wanting to have his kids forget the value of human lives or exactly what they were taking away as they sliced down enemy after enemy—but any lecture he could think of fell on death ears and was greeted with silence. Byleth understood her father’s words completely, but just couldn’t find herself to care too much. As long as her father and (more _importantly_) brother were safe, then what was the harm in taking lives?))

* * *

When Byleth pulled back the arrow, aiming for the chest of the man in front of her, something inside her pulsed. She let go of the arrow early in surprise and the arrow missed it’s intended target, but a light glowed from her chest as the man was struck down violently, not moving as he laid on the ground. She looked at him in slight surprise, staring at the arrow that stuck out of his shoulder, but shook her head and ran to catch up with her brother further in the battle. She reached him just as he struck an armored unit with his axe, his chest also glowing a bit as the axe crushed the metal armor with ease. She blinked in surprise, and slowed down to stand next to him. He gave her an equally surprised look, but with a short nod the two resolved to discuss it with Jeralt later, instead focusing on destroying the rest of the rebelling noblemen in their way.

“I think you two are talking about Crests..?” Jeralt sighed later that day, sitting down on his bed in the borrowed room he shared with the twins. Byleth crossed her legs and stared at her father as her brother simply mirrored their dad’s position, the twins staring at him in silence. Jeralt shook his head at their confused eyes and continued. “Crests are…” He stared off to the side before shaking his head and looking back at his kids. “They’re just something some noblemen tend to possess that allows them to be stronger in battle. No need to worry about it, you two definitely _don’t_ have one.” He stretched and reached for a book on his nightstand, settling onto the pillows to crack it open and read—ending the conversation. Byleth looked at her brother, who was staring at Jeralt with an unreadable expression before letting a breath of air escape his lips. He fell back against the bed and stared at the ceiling, and Byleth moved to lie down beside him, the exhaustion from the battle finally catching up with her. She lifted her hand, the one that had released the arrow that started the whole mess, and looked it over carefully. Nothing was strange about it by just appearance alone, and she accepted the answer her father gave her and dropped her hand on the bed. Byleth closed her eyes, feeling her brother rest his own hand over hers, and let herself fall asleep.

((She didn’t wake when Jeralt stood from his bed, walking over to move his kids under the covers. She didn’t even shift as he stared at the two with a worried expression, or as he blew the candle out in the room. She did wake up when a sharp pain hit her just below her stomach, groaning in her sleep and curling in around her stomach. She drifted in and out of pained sleep before a woman gently shook her awake and helped her into clean clothes, explaining the changes in her body. Byleth took the information silently, noting that the woman never mentioned crests along the slew of side effects that came with becoming an adult. She wondered if it was just another thing wrong with her.))

* * *

When Byleth cast her first spell, her father was less than impressed. The mage who was teaching her clapped a hand on her back and praised her a job well done, claiming that Fortify was a challenging spell to cast for beginners. She shyly glanced at her father and waited to hear any words of praise from him, but after seeing his upset expression Byleth turned away, lowering her hands and resting them at her sides. Her brother managed to pull off a Heal spell a few moments later, but Byleth could still see that their father was not very happy at this accomplishment either.

“Your kids are natural healers Captain!” The mage explained excitedly when Jeralt finally made his way over. He gave him a hard stare before looking to Byleth and her brother, who were standing side by side.

“…That’s nice, lets just keep the magic to a minimum okay kids?” He finally spoke, and Byleth fought through her confusion to give a nod in acknowledgement. The mage sputtered and turned on his boss, trying to explain how the twins could prove to be more helpful in battles as they learned more magic, but Byleth tuned them out in favor of looking at her brother (after all, she knew how stubborn Jeralt could be, and was sure that the meek mage wouldn’t be able to change her father’s mind). Her twin was staring at their father with a thoughtful stare before he shifted his gaze at her, slightly raising an eyebrow. Byleth shook her head, answering her brother’s silent question and raising her own eyebrow to pose her own. He turned fully to level a stare at her before he finally shook his own head. Byleth blinked at this before looking over at the swords the two discarded when the mage offered to teach them magic. Her brother got the message, and a small smirk broke on his face before they dove for the weapons. Byleth reached her sword first, and she turned quickly to slash at her unarmed brother. He rolled out of the way and grabbed his sword on the way, slashing up and causing some dirt to fly up. She coughed and jumped backwards, blocking a downward swing. The commotion caused Jeralt and the mage to stop arguing and look over, watching the twins fall into sync. He smiled at the kids, the words he was about to lob at the mage long left his mind, and settled on watching the twins spar.

((Later that day, Jeralt gently explained that he didn’t think magic was suited for the twins, despite it’s initial appeal, and that weapons were far more reliable. Byleth simply took his words without question, and while her brother asked if they could at least heal each other every so often, she settled on lying on her bedroll and ignoring the way magic seemed to flow through her body with familiar ease. She secretly hoped that Jeralt would change his mind, and that she would be able to cast spells and feel that same elated feeling she felt earlier that day.))

* * *

When Byleth first dreamed of the large battle that had large armies sprawling across a battlefield, she didn’t think too much of it. She hardly had _any_ dreams, and gladly welcomed dreams of a green haired woman brutally murdering a large man over dreams of black emptiness and cold. Sometimes she watched from afar as the woman fought, winning the battle over and over and loosing more and more of herself as she stabbed her enemy endlessly with her dagger. Sometimes she managed to force herself to move, rushing over to the woman with legs too long to be her own, shouting a name unfamiliar to her as she begged the woman to stop, to spare—never to kill—as the warm and wet sensation of tears tickled her cheeks. Even rarer where the times where Byleth dreamt she was dying, lying abandoned on a rocky surface surrounded by tall cliffs as someone sobbed over her. But it wasn’t until her brother woke her one night, a thin layer of sweat on his skin, that she thought the dreams were strange.

“…Byleth..?” She murmured and stared at her brother, who was shaking slightly. Already awake from her own nightmares, the soft moonlight gave Byleth enough light to just barely make out the features of her brother’s face, twisted with worry as he grasped her night gown. She sat up slowly, watching him calm down while still clinging to her, his own nightgown slipping off his shoulders. She gently readjusted it and wiped at his forehead.

“…I’m fine” He finally muttered, and Byleth couldn’t stop the small huff of air she let out in response. He glared at her, but she gently pulled him into a hug before her brother could protest further.

“Okay, then lets go back to sleep” She near whispered, and he nodded and nuzzled his face in the crook of her neck, finally calming down enough to breathe normally. The twins lied back down in their shared bedroll, and Byleth was almost asleep when her brother spoke again.

“…I dreamt of a large battle” He murmured, suddenly jolting Byleth out of her sleep. She blinked in surprise as he continued. “They won…and a woman was stabbing me over and over…” He pulled his sister closer to him, but Byleth could only think about her own dream, standing over a dead corpse with a strange smile on her face.

“I…had that dream too…” She confessed, and was about to explain the key difference when their father shifted in his own bed, a mere five feet away from the twins. They froze and held their breaths, watching as Jeralt simply turned over to face his kids in his sleep. As they let go of their breaths in relief, Byleth felt her brother slip back under the blankets and moved to do the same, their conversation seeming to have ended. But when she curled next to her twin to sleep, he gently grabbed her hand and laced their fingers together.

“…S-so you won’t have nightmares” He muttered, closing his eyes and squeezing her hand. Byleth smiled and squeezed back, letting her brother’s cool hand hold her own warm one, and fell asleep with him.

((Byleth still had nightmares of course, and so did her brother. They still woke up in the middle of the night, sometimes together, sometimes alone, and still had to fight away images of corpses to fall back asleep. But that night, they dreamed they were in a small, underground tomb. While her brother chased her around with a random stick and played pretend with her, Byleth’s eyes kept drifting to the stone throne that sat atop a flight of stairs at the back wall. She couldn’t shake the feeling that someone was watching them from there, even if the feeling was lonely and not unnerving.))

* * *

When Byleth was woken up for the last time as a mercenary, she tried not to groan and roll away from her father’s hands. She had finally managed to fall asleep despite the injury on her back from a stray arrow, and the way her brother had clung to her in his sleep had caused her to wake every few hours when he shifted and hit her face. Luckily, his sword (that he somehow managed to sneak in their shared bed without Jeralt yelling at him) was cradled in his other hand and was nowhere near stabbing range. In any case, Byleth was tired and not ready to wake up so early and walk for the long amount to time it would take the mercenary group to reach their next destination.

“Come on you two, get up!” Jeralt sighed, and Byleth managed to ignore his words and fall back asleep. She was finally greeted with a dream, a good indication that she was finally asleep, but it was soon ruined when an arrow sunk into her back. She gasped a bit in pain, whirling around to face her enemy, a sword having found its way in her hands, but froze when she saw the massive army approaching her, a blood red flag waving in the wind. Another arrow hit her, this time in her stomach, and Byleth doubled over in pain. Footsteps approached her, and she saw black heeled boots come into view. She coughed up blood as one boot stuck her back, knocking her onto the ground and forcing the two arrows to burry deeper inside her body. Byleth tried to raise her head to see the figure, but her vision swirled and she could only see red.

“This is what traitors deserve.” A voice above her spat out, and Byleth could see a strange spiked weapon swing down.

A sharp gasp jolted her from her dream, as her brother suddenly sat up clutching his sword. Byleth rolled to her side and curled in on herself, just as pale as her brother.

“Well good morning to you two, sleep well?” Jeralt half joked, and her father sat on the bed next to them. “Same dreams? Who had which one this time?” Her brother found his voice first.

“I…i was with some…_child!_” He nearly spat, frowning at the memory as he tossed the rest of the sheets aside to get dressed. Byleth had gone to sleep wearing her armor, knowing that slight discomfort would be worth skipping the hassle of dressing, and slowly sat up, clutching her abdomen. She ignored the sick feeling in her stomach to answer her father’s questioning eyes.

“…I was on…on a battle, battlefield,” She whispered. Jeralt nodded and patted her back in comfort, looking towards his son.

“I remember those, tough when they get swapped huh? I’d think you’d fare better with a child than a battlefield son.” He smirked a bit and helped his kids get ready. Jeralt decided to ignore his son’s snort. “Anyway, be ready to leave at daybreak.” Jeralt decided to _not_ ignore his kid’s groans. “Oh come on, everyone else is already ready.” Byleth could already feel her legs protest standing, and was about to speak when an archer burst into the room.

“Captain!” He yelled, and Jeralt groaned.

“Yes? What is it now?” He stood and walked to his subordinate quickly, and Byleth gave her brother a look before standing and rushing towards her weapons. Her twin moved to quickly finish changing, and Byleth helped him snap on his knee armor as they ran out the door to join their father. He was currently standing with his back to them, looking at three children. Well, they were only a few years younger than Byleth if she had to guess, but they looked like children all the same. The twins reached their father, each one standing on either side of him, just in time to hear him address the kids.

“Okay okay, what do we have here?” Jeralt asked the kids with a small sigh, and Byleth took the time to examine the figures in front of her. The one in the center was a blonde boy wearing black armor, a blue cape on his side matching well with his icy blue eyes. He spoke first, explaining that they were being chased by bandits and had gotten separated from their companions. This caught her attention, and Byleth focused her attention on the area behind the three, watching for any following bandits. When they started bickering, Byleth let herself steal glances to inspect the other two kids. To the left of the blonde was a boy wearing what seemed to be some sort of uniform, and his yellow cape matched nicely with the gold details on his outfit. He was talking with his hands, defending himself as his companions pushed the fault onto him, but Byleth could see the beginnings of a playful smile. The third person was a woman, wearing bright red tights to match her bright red cape. The red was familiar, and just as Byleth realized where she saw it before, the archer cried out in alarm.

“Captain! They’re on their way over!” The kids whirled around in surprise, and Byleth was suddenly overcome with the desire to shield the kids from any harm.

“Get in battle formation!” Jeralt called out to his men, who stopped packing up camp in favor of grabbing their weapons. “Byleth, you take the boys and start thinning their numbers. Byleth, _you_ the, uh, female and I will flank them and find their commander” Her father ordered, and Byleth watched her brother dash off, nearly leaving the two boys in his dust. As they raced off to catch up, she turned her attention to the girl who wore the same red as the figure in her dreams. She was holding a simple training axe, and Byleth gently leaded her to Jeralt’s horse, where he would mount and use his lance to attack. The female seemed a bit worried, and Byleth couldn’t help the words from falling out of her mouth.

“It’ll be okay,” She stated, surprising the female along with herself. She felt the burn of questioning eyes on her as she grabbed the bow quiver Jeralt kept on his horse just in case, and decided to let herself continue. “It’ll be okay, I’ll make sure you don’t get hurt.” Byleth turned to give the female a (hopefully) comforting nod, and she saw the stress finally ebb out of the girl’s body. Jeralt joined them, and the three made their way to the battle field.

Her brother was already in combat, slashing his sword at enemies as the yellow caped kid used his arrows to provide cover. The blue caped boy was right behind her twin, using his lance to jab at enemies and keep them at a safe distance. Byleth noted the way they worked seamlessly together before shifting her focus, her sword slicing at an arrow that was lobbed at her and the girl. She moved to become a shield for the girl and used her own arrow to hit back, quickly kicking away another enemy that got too close for comfort. The red caped girl used her axe fairly well, using the back end of the weapon to knock back a bandit far enough for Byleth to swing and slice through the man’s armor, and the two fell in sync with her father to clear enemies and make their way to join the other three.

Byleth cursed herself for being stupid. She had just cut down the enemy commander, and had turned her back to look for her brother to ensure he wasn’t injured. She didn’t notice that the man had jumped back up, or that he was charging for the female. She whirled her head as she heard a small dagger being unsheathed, and raced to shield the female noble.

“You’ll DIE!!” The man yelled, and Byleth had just enough time to grab the girl by her cape and pull her to her body, twisting and pressing the female close to her chest. She closed her eyes as she waited the blade of the axe to slice into her skin, feeling a pang of remorse for no longer being able to protect her brother, before time froze around her. Everything around her melted away, and she opened her eyes when the pain didn’t come. She looked around, finding herself in a black and empty space, only to lock eyes with her brother. He had curled up to shield something( or _someone_), but he too stood up and looked at her in confusion.

“Honestly! What were you accomplishing with that little stunt?! It’s like you’re _trying_ to get me killed, you fools! Or even worse, _each other_!” A voice called out, and Byleth’s eyes widened at the familiarity of it. She spun around and saw a large stone throne, and the green haired girl sitting on it sighed and shook her head, a small smile forming on her lips. Her brother had moved to stand next in front of her, frowning in confusion at her words, but Sothis simply sighed again. “Well it’s _fine_. After all, if you don’t know the value of your own life, you’re not going to protect it very well, are you? Of course not…” Byleth found herself not confused at Sothis’s words at all, instead comforted as the girl sat up and stood, and she could feel herself relaxing next to her brother, who only tensed up.

“Well then, I guess it’s up to me to guide you from now on, right?” Sothis smiled down at the twins, and chucked a bit. “Or I guess I should say, guide you _again_” Byleth smiled at her words and the two females shared a knowing smile as her brother frowned with more confusion. Sothis continued to speak from her place high above the twins “You,” She started, looking at the male twin, “can call me Sothis, but” She shifted to gaze at the female. “I’m also known as ‘the Beginning’.” Sothis smiled down at the twins, admiring at how big they’ve gotten. She was fully refreshed and ready to see the world with them, and was only _slightly_ annoyed that they nearly gotten themselves killed.

((Sothis sighed as the stared at the two figures in front of her. She had just managed to regain her strength enough to awaken and offer her assistance to them, and they go and nearly get themselves killed. She shook her head as a thought wormed it’s way into her mind: ‘Twins are dangerous’.))

**Author's Note:**

> That was part one! I'm working on the second part, where we'll follow the twins as they enter the monastery and start teaching, but I'm working on the male and female twins' stories at the same time. I'm planning on at least three/four parts, with one bonus chapter exploring my ships for the AU. Sorry for the wait, hope you like it!
> 
> Also, I would recommend you read Male Byleth's story. It's like the opposite side of the coin, some gaps in this story are filled in that one and vice versa. Of course, it's not necessary; but if you're confused I highly recommend it.


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